Scilab Function
Last update : 16/12/2004

graypolarplot - Polar 2D plot of a surface using colors

### Calling Sequence

  `graypolarplot(theta,rho,z,[strf,rect])`

### Parameters

- `rho`: a vector with size n1, the discretization of the radius
- `theta`: a vector with size n2, the discretization of the the angle.
- `z`: real matrix of size (n1,n2). `z(i,j)` is the value of the surface at the point (rho(i),theta(j)).
- `strf`: is a string of length 3 `"xy0"`.
  - `default`The default is `"030"`.
  - `x`: controls the display of captions.
    - `x=0`: no captions.
    - `x=1`: captions are displayed. They are given by the optional argument `leg`.
  - `y`: controls the computation of the frame.
    - `y=0`: the current boundaries (set by a previous call to another high level plotting function) are used. Useful when superposing multiple plots.
    - `y=1`: the optional argument `rect` is used to specify the boundaries of the plot.
    - `y=2`: the boundaries of the plot are computed using min and max values of `x` and `y`.
    - `y=3`: like `y=1` but produces isoview scaling.
    - `y=4`: like `y=2` but produces isoview scaling.
    - `y=5`: like `y=1` but `plot2d` can change the boundaries of the plot and the ticks of the axes to produce pretty graduations. When the zoom button is activated, this mode is used.
    - `y=6`: like `y=2` but `plot2d` can change the boundaries of the plot and the ticks of the axes to produce pretty graduations. When the zoom button is activated, this mode is used.
    - `y=7`: like `y=5` but the scale of the new plot is merged with the current scale.
    - `y=8`: like `y=6` but the scale of the new plot is merged with the current scale.
- `leg`: a string. It is used when the first character x of argument `strf` is 1. `leg` has the form `"leg1@leg2@...."` where `leg1`, `leg2`, etc. are respectively the captions of the first curve, of the second curve, etc. The default is `""`.
- `rect`: This argument is used when the second character y of argument `strf` is 1, 3 or 5. It is a row vector of size 4 and gives the dimension of the frame: `rect=[xmin,ymin,xmax,ymax]`.

### Description

Takes a 2D plot of the surface given by `z` on a polar coordinate grid defined by `rho` and `theta`. Each grid region if filled with a gray or color level depending on the average value of `z` on the corners of the grid.

### Examples

      rho=1:0.1:4;theta=(0:0.02:1)*2*%pi;
      z=30+round(theta'*(1+rho^2));
      f=gcf();
      f.color_map= hotcolormap(128);
      clf();graypolarplot(theta,rho,z)